a) Field of the Invention
The invention is directed to an adjusting device for positioning a load, comprising a spindle-type lifting gear with a spindle, a spindle nut arranged on the spindle, and a gear unit housing having first and second bearing bushes at opposite side surfaces, the spindle or the spindle nut and a driveshaft for driving the spindle or the spindle nut being rotatably supported in the gear unit housing, first and second bearing brackets, each with a stand and an arm which projects therefrom and which has, in an end portion adjoining its free end, a bearing pin that engages in a respective bearing bush of the gear unit housing for the swivelable bearing support of the gear unit housing of the spindle-type lifting gear, a driving motor with a motor shaft, and a motor flange unit with a flange housing that is rigidly connected to the driving motor on one side and to the gear unit housing on the other side, and a coupling arranged in the flange housing for transmitting torque from the motor shaft to the driveshaft of the spindle-type lifting gear.
b) Description of the Related Art
Adjusting devices for positioning a load having spindle-type lifting gears, also called spindle nut gears, are known in various embodiment forms. Adjusting devices of this type are used for positioning loads in the form of structural component parts or component assemblies. For example, these adjusting devices are used in lifting platforms, lifting jacks, vertically adjustable platforms, valves with valve slides that are adjustable by motor, forms for concrete that are adjustable by motor, and so on.
Besides spindle-type lifting gears in which the spindle nut is mounted in bearings in a gear unit housing so as to be rotatable and fixed with respect to axial displacement and in which a spindle which is fixed with respect to relative rotation is adjusted in axial direction during the rotation of the spindle nut, there are also known spindle-type lifting gears in which the spindle is mounted in bearings in the gear unit housing so as to be rotatable and fixed with respect to axial displacement and in which a spindle nut which is arranged on the male thread of the spindle and fixed with respect to rotation is adjusted in axial direction of the spindle during the rotation of the spindle.
The spindle nut or spindle is driven by means of a driving motor whose motor shaft is coupled with a driveshaft projecting out of the gear unit housing of the spindle-type lifting gear. Motor flange units for facilitating the connection of the driving motor and the spindle-type lifting gear are already known. These motor flange units comprise a flange housing and a coupling arranged in the flange housing. The flange housing is fastened to the gear unit housing of the spindle-type lifting gear on one side and to the housing of the driving motor on the other side so that generally it is possible for the driving motor to be held at the gear unit housing so that a separate bearing support of the driving motor can be dispensed with. When connecting the flange housing to the gear unit housing and the motor housing, a connection is produced at the same time between the driveshaft of the spindle-type lifting gear and of the motor shaft of the driving motor and the coupling of the motor flange unit so that the torque-transmitting connection is formed between the motor shaft and the driveshaft.
In applications in which the adjusting device swivels a load around a swiveling axis, the swiveling of the load also brings about a (generally smaller) swiveling of the gear unit housing of the spindle-type lifting gear around a swiveling axis. Adapter pieces are usually provided to enable a swiveling bearing support of the gear unit housing for applications of this type. The gear unit housing can be screwed into these adapter pieces which have bearing bushes or bearing pins. Bearing pins or bearing bushes of bearing brackets arranged at a stationary carrying part, for example, a supporting table, cooperate with these bearing bushes or bearing pins of the adapter pieces, and the load is swiveled around a swiveling axis relative to this carrying part. Further, the load is swivelably connected to the spindle (in case of an axially adjustable spindle) or to the spindle nut (in case of an axially adjustable spindle nut). A swivelable bearing support of the adapter pieces connected to the gear unit housing at the swivelable load and a swivelable bearing support of the axially adjustable spindle or axially adjustable spindle nut at a stationary carrying part, for example, a supporting table, can also be provided. The additional adapter pieces lead to additional expenditure in production and assembly.
Another adjusting device of the type mentioned above is known from AT 008 083 U1 which shows and describes the spindle-type lifting gear and bearing brackets of this device. The bearing bushes for the swivelable bearing support of the spindle-type lifting gear are arranged directly in the gear unit housing in this device, and pocket holes in which sliding bushes are inserted are formed at opposite side surfaces of the gear unit housing. The bearing pins of bearing brackets project into these bearings bushes for the swivelable bearing support of the gear unit housing. The bearing pins are arranged at arms which project from the stands and which are formed in the shape of an inverted V.
For reasons of space (because a compact construction of the gear unit housing of the spindle-type lifting gear is desirable), the bearing bushes and the driveshaft in this previously known adjusting device of the type mentioned above are arranged at side surfaces of the gear unit housing which extend at right angles to one another, i.e., the swiveling axis and the axis of the driveshaft are at right angles to one another. When the driving motor is arranged at the gear unit housing by means of a motor flange unit, the weight of the driving motor can lead to an undesirably high torque around the swiveling axis of the gear unit housing depending on the position of the gear unit housing.